Prediction of treatment efficacy and telaprevir-resistant variants after triple therapy in patients infected with hepatitis C virus genotype 1. J Clin Microbiol. 2013;51:2862-2868. [PMID: 23784126 DOI: 10.1128/jcm.01129-13]

In search of a function for human type III interferons: insights from inherited and acquired deficits

The essential and redundant functions of human type I and II interferons (IFNs) have been delineated over the last three decades by studies of patients with inborn errors of immunity or their autoimmune phenocopies, but much less is known about type III IFNs. Patients with cells that do not respond to type III IFNs due to inherited IL10RB deficiency display no overt viral disease, and their inflammatory disease phenotypes can be explained by defective signaling via other interleukine10RB-dependent pathways. Moreover, patients with inherited deficiencies of interferon-stimulated gene factor 3 (ISGF-3) (STAT1, STAT2, IRF9) present viral diseases also seen in patients with inherited deficiencies of the type I IFN receptor (IFNAR1/2). Finally, patients with autoantibodies neutralizing type III IFNs have no obvious predisposition to viral disease. Current findings thus suggest that type III IFNs are largely redundant in humans. The essential functions of human type III IFNs, particularly in antiviral defenses, remain to be discovered.

Human genetics of HCV infection phenotypes in the era of direct-acting antivirals

The recent introduction of direct-acting antivirals (DAAs) has revolutionized hepatitis C virus (HCV) therapy by improving virus eradication rates to over 90% in most patient groups. However, the impact of DAAs on global disease burden is currently limited, and a large number of chronically infected individuals remain at risk of developing liver complications, such as liver cirrhosis and hepatocellular carcinoma (HCC). The identification of patients at risk of liver complications and a greater understanding of the biological mechanisms involved in HCV disease progression might improve disease control. Recent genome-wide association and exome sequencing studies have identified several host genetic variants influencing the progression of liver fibrosis and the development of HCC associated with HCV infection and are reviewed here. Interestingly, some of the genetic variants associated with those HCV-associated liver complications were also associated with the clinical course of non-viral chronic hepatitis. Future challenges include the incorporation of this genetic information into clinical risk models for personalized disease management and the study of emerging phenotypes such as liver fibrosis regression and HCC development after HCV eradication.

Optimisation of triple therapy for patients with chronic hepatitis C: a systematic review

BACKGROUND

Triple therapy with Pegylated-Interferon α (PEG-IFNα)/Ribavirin (RBV) and Boceprevir (Boc) or Telaprevir (Tel) significantly improved sustained virological response (SVR) rates for patients with genotype 1 HCV infection compared to PEG-IFNα/RBV alone (dual therapy). However, less is known about factors associated with rates of SVR and of adverse events (AEs).

MATERIAL AND METHODS

The aim of this systematic review was to evaluate the evidence regarding the factors affecting response and rate of AEs associated with triple therapy. We performed systematic electronic searches in Medline, Embase, Scopus and Central as well as a list of reference literature. We included randomised controlled trials examining triple therapy compared with dual therapy and reporting data according to patients features and about AEs. Odds ratios (OR) were pooled using either fixed or random effect model, as appropriate.

RESULTS

We included data from 14 studies. Treatment with triple therapy increased SVR rate compared to dual therapy especially in patients previously treated with PEG-IFNα/RBV and with increased pretreatment alanine aminotransferase (ALT) levels. Higher rate of serious AEs and treatment discontinuation due to AEs was also observed particularly in treatment-experienced patients.

CONCLUSIONS

The present study shows how improved results of triple therapy are mainly observed in some patients' subsets and are accompanied by increased risk of AEs compared to dual therapy. These results might be useful for optimising treatment of chronic hepatitis C when IFN-free regimens are unavailable.

HCV inter-subtype 1a/1b recombinant detected by complete-genome next-generation sequencing

Next-generation sequencing (NGS) provides a practical approach to HCV complete-genome sequencing, detecting low-frequency variants and allowing analysis of viral genetic diversity (quasispecies) in the sample, and so far, it is very useful for identifying preexisting drug-resistant mutants and emerging escape mutations, as well as detecting viral recombinants containing genomic regions from different genotypes and subtypes. The aim of this study was to analyze the complete coding region of hepatitis C virus (HCV) genotype 1 (subtypes 1a and 1b) from patients with chronic infection who were direct-acting antiviral (DAA) naïve. Next-generation sequencing (Ion Torrent™ PGM) was used to determine the sequence of the complete coding region of 100 HCV-monoinfected DAA-naïve patients (51 and 49 subtypes 1a and 1b, respectively). We report the first description of nearly complete HCV genome sequences of subtype 1a and 1b isolates from a large population of Brazilian patients with chronic hepatitis C, and HCV-1a grouped in two different clades. Using this methodology, an inter-subtype 1a/1b recombinant was identified in this study.

HCV evolutionary genetics of SVR versus virologic failure assessed from the vaniprevir phase III registration trials

In the phase III registration studies conducted in Japan, Japanese HCV gt1 patients administered vaniprevir 300 mg twice daily plus pegylated interferon/ribavirin for 12 or 24 weeks achieved SVR24 rates of 83.7-84.5% among treatment-naïve patients, and 92.0-96.2% and 61.9% among breakthrough/relapsers or null-responders to prior interferon based therapy. As evidenced by direct sequencing, patients who did not achieve SVR24 principally failed due to treatment-emerging mutations at D168 or in a few cases R155. In this work, additional sequence analysis was conducted to address whether there were baseline polymorphisms associated with failure, evaluate the persistence of resistant virus among treatment failures, and assess for evidence of second site co-evolution with R155 or D168 mutations. To accomplish this, clonal sequencing (up to 40 clones per sample) was conducted on baseline, failure, and follow-up samples from all 38 patients among the vaniprevir treatment arms who met virologic failure criteria (37 gt1b, 1 gt1a, herein referred to as virologic failures) and baseline samples from 41 vaniprevir-treated SVR24 patients (all gt1b) selected among the three studies. SVR24 and virologic failure patients showed similar distributions of baseline polymorphisms previously associated with failure to one or more protease inhibitors. Furthermore, there was no evidence for baseline polymorphisms or a genetic signature across the NS3 protease domain specific to virologic failure patients, and which distinguishes them from baseline SVR24 sequences beyond a chance distribution. 24 of 32 virologic failures for whom baseline, failure, and follow-up samples were available showed reduced prevalence of the resistant virus first observed at the time of failure during the protocol-defined follow-up period of 24 weeks. Finally, pairwise analysis using either alignment or phylogenetic based methodologies provided no evidence for second site evolution with either the R155 or D168 mutations attributed to failure. This work supports and extends earlier findings based upon direct sequencing that attributed virologic failure to vaniprevir in the Phase III studies solely to the emergence of R155 or D168 mutations, with no apparent influence by other residues within the NS3 protease domain on treatment outcome. CLINICALTRIALS.

GOVIDENTIFIERS

NCT01370642, NCT01405937, NCT01405560.

Impact of IL28B, APOH and ITPA Polymorphisms on Efficacy and Safety of TVR- or BOC-Based Triple Therapy in Treatment-Experienced HCV-1 Patients with Compensated Cirrhosis from the ANRS CO20-CUPIC Study

BACKGROUND

Human genetic factors influence the outcome of pegylated interferon and ribavirin hepatitis C therapy. We explored the role of IL28B, APOH and ITPA SNPs on the outcomes of triple therapy including telaprevir or boceprevir in patients with compensated cirrhosis chronically infected with HCV-1.

PATIENTS AND METHODS

A total of 256 HCV-1 Caucasian treatment-experienced patients with compensated cirrhosis from the ANRS CO20-CUPIC cohort were genotyped for a total of 10 candidate SNPs in IL28B (rs12979860 and rs368234815), APOH (rs8178822, rs12944940, rs10048158, rs52797880, rs1801689 and rs1801690) and ITPA (rs1127354 and rs7270101). We tested the association of IL28B and APOH SNPs with sustained virological response and of ITPA SNPs with anemia related phenotypes by means of logistic regression assuming an additive genetic model.

RESULTS

None of the six APOH SNPs were associated with sustained virological response. The favorable alleles of the IL28B SNPs rs12979860 and rs368234815 were associated with sustained virological response (rs12979860: OR = 2.35[1.50-3.70], P = 2x10(-4)). Refined analysis showed that the effect of IL28B SNPs on sustained virological response was restricted to prior PegIFN/RBV relapse (OR = 3.80[1.82-8.92], P = 8x10(-4)). We also confirmed the association between ITPA low activity alleles and protection against early hemoglobin decline in triple therapy (P = 2x10(-5)).

CONCLUSION

Our results suggest that the screening of rs12979860 may remain interesting for decision making in prior relapse HCV-1 Caucasian patients with compensated cirrhosis eligible for a telaprevir- or boceprevir-based therapy.

Evolution of simeprevir-resistant variants in virological non-responders infected with HCV genotype 1b

The present study was designed to assess the evolution of simeprevir-resistant variants (amino acid substitutions of aa80, aa155, aa156, and aa168 positions in HCV NS3 region) over time in virological non-responders (patients with positive HCV-RNA during and at end of treatment). The study enrolled 136 patients infected with HCV genotype 1b who received 12-week simeprevir-PEG-IFN-ribavirin therapy, and data of 87 patients were available for analysis. Twelve patients (14%) were considered virological non-responders, including 9 (75%) who showed absolute no-response (HCV RNA: ≥3.0 log IU/ml at 12 weeks after start of therapy). Multivariate analysis of these patients identified lack of response to prior treatment, use of low ribavirin dose, and old age as independent and significant determinants of virological non-response. Using ultra-deep sequencing, de novo variants of D168 were detected in all of 9 absolute non-responders. The majority of these variants emerged within 5 weeks of triple therapy. In comparison, de novo variants of Q80 were detected in only 3 of 9 absolute non-responders and emerged at 6-12 weeks. Variants of Q80 detected at baseline increased during the course of treatment in 5 of 9 absolute non-responders, while no such increase was noted in variants of R155 and/or A156 detected at baseline during the 12-week course. De novo variants of R155 and/or A156 were not detected in this study. The results demonstrated the emergence of simeprevir-resistant variants during the early stage of triple therapy.

Deep sequencing and phylogenetic analysis of variants resistant to interferon-based protease inhibitor therapy in chronic hepatitis induced by genotype 1b hepatitis C virus

Because of recent advances in deep sequencing technology, detailed analysis of hepatitis C virus (HCV) quasispecies and their dynamic changes in response to direct antiviral agents (DAAs) became possible, although the role of quasispecies is not fully understood. In this study, to clarify the evolution of viral quasispecies and the origin of drug-resistant mutations induced by interferon (IFN)-based protease inhibitor therapy, the nonstructural-3 (NS3) region of genotype 1b HCV in 34 chronic hepatitis patients treated with telaprevir (TVR)/pegylated interferon (PEG-IFN)/ribavirin (RBV) was subjected to a deep sequencing study coupled with phylogenetic analysis. Twenty-six patients (76.5%) achieved a sustained viral response (SVR), while 8 patients did not (non-SVR; 23.5%). When the complexity of the quasispecies was expressed as the mutation frequency or Shannon entropy value, a significant decrease in the IFNL3 (rs8099917) TT group and a marginal decrease in the SVR group were found soon (12 h) after the introduction of treatment, whereas there was no decrease in the non-SVR group and no significant decrease in mutation frequency in the IFNL3 TG/GG group. In the analysis of viral quasispecies composition in non-SVR patients, major populations greatly changed, accompanied by the appearance of resistance, and the compositions were unlikely to return to the pretreatment composition even after the end of therapy. Clinically TVR-resistant variants were observed in 5 non-SVR patients (5/8, 62.5%), all of which were suspected to have acquired resistance by mutations through phylogenetic analysis. In conclusion, results of the study have important implications for treatment response and outcome in interferon-based protease inhibitor therapy.

IMPORTANCE

In the host, hepatitis C virus (HCV) consists of a variety of populations (quasispecies), and it is supposed that dynamic changes in quasispecies are closely related to pathogenesis, although this is poorly understood. In this study, recently developed deep sequencing technology was introduced, and changes in quasispecies associated with telaprevir (TVR)/pegylated interferon (PEG-IFN)/ribavirin (RBV) triple therapy and their clinical significance were investigated extensively by phylogenetic tree analysis. Through this study, the associations among treatment response, changes in viral quasispecies complexity in the early stage of treatment, changes in the quasispecies composition, and origin of TVR-resistant variant HCV were elucidated.

Advanced molecular surveillance of hepatitis C virus

Hepatitis C virus (HCV) infection is an important public health problem worldwide. HCV exploits complex molecular mechanisms, which result in a high degree of intrahost genetic heterogeneity. This high degree of variability represents a challenge for the accurate establishment of genetic relatedness between cases and complicates the identification of sources of infection. Tracking HCV infections is crucial for the elucidation of routes of transmission in a variety of settings. Therefore, implementation of HCV advanced molecular surveillance (AMS) is essential for disease control. Accounting for virulence is also important for HCV AMS and both viral and host factors contribute to the disease outcome. Therefore, HCV AMS requires the incorporation of host factors as an integral component of the algorithms used to monitor disease occurrence. Importantly, implementation of comprehensive global databases and data mining are also needed for the proper study of the mechanisms responsible for HCV transmission. Here, we review molecular aspects associated with HCV transmission, as well as the most recent technological advances used for virus and host characterization. Additionally, the cornerstone discoveries that have defined the pathway for viral characterization are presented and the importance of implementing advanced HCV molecular surveillance is highlighted.

Ultradeep pyrosequencing of NS3 to predict response to triple therapy with protease inhibitors in previously treated chronic hepatitis C patients

Despite the gain in sustained virological responses (SVR) provided by protease inhibitors (PIs), failures still occur. The aim of this study was to determine if a baseline analysis of the NS3 region using ultradeep pyrosequencing (UDPS) can help to predict an SVR. Serum samples from 40 patients with previously nonresponding genotype 1 chronic hepatitis C who were retreated with triple therapy, including a PI, were analyzed. Baseline UDPS of the NS3 gene was performed on plasma and peripheral blood mononuclear cells (PBMC). Mutations conferring resistance to PIs were sought. The overall diversity of the quasispecies was evaluated by calculating the Shannon entropy (SE). Resistance mutations were found in plasma and PBMC but were not discriminating enough to predict an SVR. NS3 quasispecies heterogeneity was significantly lower at baseline in patients achieving an SVR than in those not achieving an SVR (SE of 26.98 ± 16.64 × 10(-3) versus 44.93 ± 19.58 × 10(-3), P = 0.0047). With multivariate analysis, the independent predictors of an SVR were fibrosis of stage F ≤2 (odds ratio [OR], 13.3; 95% confidence interval [CI], 1.25 to 141.096; P < 0.03) and SE below the median (OR, 5.4; 95% CI, 1.22 to 23.87; P < 0.03). More than the presence of minor mutations at the baseline in plasma or in PBMC, the NS3 viral heterogeneity determined by UDPS is an independent factor for an SVR in previously treated patients receiving triple therapy that includes a PI.

No correspondence between resistance mutations in the HCV-NS3 protease at baseline and early telaprevir-based triple therapy

Direct-acting antiviral (DAA)-based therapy is the new standard treatment for chronic hepatitis C virus (HCV) infection. However, protease inhibitor (PI)-resistant viral variants have been often described. This study aimed to examine HCV-NS3 protease variants at baseline and at 4 weeks under triple therapy. To this end, we analyzed the presence of variants in HCV-NS3 protease region from peripheral blood samples of 16 patients infected with HCV-1 at baseline and at 4 weeks of combined therapy with telaprevir, pegylated interferon, and ribavirin, using next-generation sequencing. Several variants with synonymous and non-synonymous amino acid substitutions were detected at both time points. Variants detected at low frequency corresponded to 74% (HCV-1a) and 35% (HCV-1b) of non-synonymous substitutions. We found nine PI-resistance-associated variants (V36A, T54S, V55I, Q80K, Q80R, V107I, I132V, D168E, M175L) in HCV-NS3 of 10 patients. There was no correspondence of resistance-associated variant profile between baseline and at 4 weeks. Moreover, these resistance variants at baseline and short-term treatment are not good predictors of outcome under triple therapy. Our study also shows a large number of others minor and major non-synonymous variants in HCV-NS3 early in telaprevir-based therapy that can be important for further drug resistance association studies with newly developed PI agents.

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HCV-NS3 protease variants were analyzed at baseline and 4 weeks of triple therapy.

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Synonymous and non-synonymous variants, even at low frequency, were detected.

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Nine PI resistance mutations were identified in 10/16 patients in both time points.

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There was no correspondence between resistance mutation at baseline and 4 weeks.

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We provide a comprehensive databank of non-synonymous variants in HCV-NS3.

A 48-week telaprevir-based triple combination therapy improves sustained virological response rate in previous non-responders to peginterferon and ribavirin with genotype 1b chronic hepatitis C: A multicenter study

AIM

The sustained virological response (SVR) rate of non-responders to peginterferon and ribavirin therapy (PR) is low for 24-week telaprevir-based triple combination therapy (T12PR24), compared to that of treatment-naïve patients or previous-treatment relapsers. This study investigated which characteristics of non-responders were associated with a better SVR rate to 48-week therapy (T12PR48).

METHODS

A total of 103 Japanese non-responders with genotype 1b chronic hepatitis C received telaprevir-based therapy. Among them, 81 patients (50 partial and 31 null responders) received T12PR24 and 22 (seven partial and 15 null responders) who agreed to the extended therapy received T12PR48.

RESULTS

Multivariate logistic regression analysis for SVR identified the interleukin-28B (IL28B) rs8099917 TT genotype (P = 0.0005, odds ratio [OR] = 10.38), extended rapid virological response (P = 0.0008, OR = 7.02), T12PR48 regimen (P = 0.0016, OR = 9.31) and previous partial responders (P = 0.0022, OR = 5.89). Among partial responders, the SVR rate did not differ significantly between T12PR48 (85.7%) and T12PR24 (70.0%). Among null responders, the SVR rate was significantly higher with T12PR48 than T12PR24 (66.7% vs 22.6%, P = 0.0037). Among patients with the IL28B non-TT genotype, the SVR rate was significantly higher with T12PR48 than T12PR24 (68.8% vs 37.7%, P = 0.0288). Moreover, among null responders with the non-TT genotype, the SVR rate was significantly higher with T12PR48 than T12PR24 (66.7% vs 9.1%, P = 0.0009).

CONCLUSION

T12PR48 improves the SVR rate in null responders, patients with the non-TT genotype, and null responders with a non-TT genotype.

Baseline factors and very early viral response (week 1) for predicting sustained virological response in telaprevir-based triple combination therapy for Japanese genotype 1b chronic hepatitis C patients: a multicenter study

BACKGROUND

Genetic polymorphisms near Interleukin 28B (IL28B) (rs8099917) and a rapid virological response (RVR) have been reported as predictors for a sustained virological response (SVR) to telaprevir (TVR)-based triple combination therapy. However, the association between SVR and viral kinetics earlier than week 4 after initiation of therapy remains unclear. Thus, we evaluated the SVR prediction ability of baseline factors and reduced hepatitis C virus (HCV) RNA levels at week 1 after the initiation of TVR-based therapy in Japanese genotype-1b chronic hepatitis C (CHC) patients.

METHODS

A total of 156 Japanese CHC patients received a 24-week regimen of TVR-based therapy. Baseline factors and reduction in HCV RNA levels at weeks 1 and 4 after the initiation of therapy were analyzed for SVR prediction.

RESULTS

Multiple logistic regression analysis for SVR in TVR-based therapy identified the IL28B TT genotype, a reduction of ≥ 4.7 log10 IU/mL in HCV RNA levels at week 1, RVR, and treatment-naïve/relapse. Whereas the SVR rate was higher than 90 % regardless of the reduction in HCV RNA levels at week 1 in patients with the TT genotype, a reduction of ≥ 4.7 log10 IU/mL in HCV RNA levels at week 1 was the strongest predictor of SVR in patients with the non-TT genotype, as determined by multiple logistic regression analysis (P = 0.0043).

CONCLUSIONS

The IL28B TT genotype is the most important baseline factor for predicting SVR, and a ≥ 4.7 log10 IU/mL reduction in HCV RNA at week 1 is a useful very early on-treatment predictor of SVR, especially in the non-TT genotype.

Prediction of Sustained Virological Response to Telaprevir-Based Triple Therapy Using Viral Response within 2 Weeks

The aim of the present study was to predict sustained virological response (SVR) to telaprevir with pegylated interferon (PEG-IFN) and ribavirin using viral response within 2 weeks after therapy initiation. Thirty-six patients with genotype 1 hepatitis C virus (HCV) and high viral load were treated by telaprevir-based triple therapy. SVR was achieved in 72% (26/36) of patients. Significant differences between the SVR group and non-SVR group were noted regarding response to prior PEG-IFN plus ribavirin, interleukin (IL)28B polymorphism, amino acid substitution at core 70, cirrhosis, hyaluronic acid level, and HCV-RNA reduction within 2 weeks. Setting 4.56 logIU/mL as the cut-off value for HCV-RNA reduction at 2 weeks, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for predicting SVR were 77%, 86%, 95%, 50%, and 79%, respectively, and for neither the IL28B minor allele nor core 70 mutant were 80%, 71%, 91%, 50%, and 78%, respectively. In conclusion, evaluation of viral reduction at 2 weeks or the combination of IL28B polymorphism and amino acid substitution at core 70 are useful for predicting SVR to telaprevir with PEG-IFN and ribavirin therapy.

Impact of hepatitis C virus heterogeneity on interferon sensitivity: an overview

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. HCV is able to evade host defense mechanisms, including both innate and acquired immune responses, to establish persistent infection, which results in a broad spectrum of pathogenicity, such as lipid and glucose metabolism disorders and hepatocellular carcinoma development. The HCV genome is characterized by a high degree of genetic diversity, which can be associated with viral sensitivity or resistance (reflected by different virological responses) to interferon (IFN)-based therapy. In this regard, it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome. In particular, among the HCV proteins, the core and nonstructural proteins (NS) 5A have been extensively studied for their correlation with responses to IFN-based treatment. This review aims to cover updated information on the impact of major HCV genetic factors, including HCV genotype, mutations in amino acids 70 and 91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A, on virological responses to IFN-based therapy.

Individualization of chronic hepatitis C treatment according to the host characteristics

Hepatitis C virus (HCV) infection is a global health problem that affects more than 170 million people worldwide. It is a major cause of cirrhosis and hepatocellular carcinoma, making the virus the most common cause of liver failure and transplantation. The standard-of-care treatment for chronic hepatitis C (CHC) has been changed during the last decade and direct acting antiviral drugs have already been used. Besides, understanding of the pathogenesis of CHC has evolved rapidly during the last years and now several host factors are known to affect the natural history and response to treatment. Recent genome-wide association studies have shown the important role of interleukin-28B and inosine triphosphatase in HCV infection. The present review article attempts to summarize the current knowledge on the role of host factors towards individualization of HCV treatment.

α-Fetoprotein is a surrogate marker for predicting treatment failure in telaprevir-based triple combination therapy for genotype 1b chronic hepatitis C Japanese patients with the IL28B minor genotype

Even when treated with telaprevir-based triple therapy, some patients fail to achieve a sustained virological response. This study identified factors related closely to treatment failure. A total of 146 Japanese genotype 1b chronic hepatitis C patients were enrolled in this prospective, multicenter study and received a 24-week regimen of triple therapy. The end-of-treatment response rate was significantly lower in patients with the interleukin 28B (IL28B) (rs8099917) non-TT genotype (85.2%) than in those with the TT genotype (100%, P = 0.0002). Multiple logistic regression analysis identified high α-fetoprotein levels as an independent factor related to non-end-of-treatment response in patients with the non-TT genotype. A cut-off value of 20 ng/ml was determined for a non-end-of-treatment response; sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 75.0%, 95.7%, 75.0%, 75.0%, and 92.6%, respectively. Multiple logistic regression analysis for a sustained virological response identified the IL28B TT genotype, low α-fetoprotein levels, non-responders, and a rapid virological response. The sustained virological response rate was significantly lower in patients with the non-TT genotype (59.3%) than in those with the TT genotype (96.7%, P < 0.0001). In patients with the non-TT genotype, α-fetoprotein was the most significant predictor for non-sustained virological response by univariate analysis. A cut-off value of 7.4 ng/ml α-fetoprotein was determined for non-sustained virological response; sensitivity, specificity, PPV, NPV, and accuracy were 63.6%, 87.5%, 77.8%, 77.8%, and 77.8%, respectively. For the non-TT patients, serum α-fetoprotein levels may be a surrogate marker for predicting treatment failure in telaprevir-based therapy for genotype 1b chronic hepatitis C.

Utility of detection of telaprevir-resistant variants for prediction of efficacy of treatment of hepatitis C virus genotype 1 infection

The clinical usefulness of detecting telaprevir-resistant variants is unclear. Two hundred fifty-two Japanese patients infected with hepatitis C virus (HCV) genotype 1b received triple therapy with telaprevir-peginterferon (PEG-IFN)-ribavirin and were evaluated for telaprevir-resistant variants by direct sequencing at baseline and at the time of reelevation of the viral load. An analysis of the entire group indicated that 76% achieved a sustained virological response. Multivariate analysis identified a PEG-IFN dose of <1.3 μg/kg of body weight, an IL28B rs8099917 genotype (genotype non-TT), detection of telaprevir-resistant variants of amino acid (aa) 54 at baseline, nonresponse to prior treatment, and a leukocyte count of <5,000/mm(3) as significant pretreatment factors for detection of telaprevir-resistant variants at the time of reelevation of the viral load. In 63 patients who showed nonresponse to prior treatment, a higher proportion of patients with no detected telaprevir-resistant variants at baseline (54%) achieved a sustained virological response than did patients with detected telaprevir-resistant variants at baseline (0%). Furthermore, 2 patients who did not have a sustained virological response from the first course of triple therapy with telaprevir received a second course of triple therapy with telaprevir. These patients achieved a sustained virological response by the second course despite the persistence of very-high-frequency variants (98.1% for V36C) or a history of the emergence of variants (0.2% for R155Q and 0.2% for A156T) by ultradeep sequencing. In conclusion, this study indicates that the presence of telaprevir-resistant variants at the time of reelevation of viral load can be predicted by a combination of host, viral, and treatment factors. The presence of resistant variants at baseline might partly affect treatment efficacy, especially in those with nonresponse to prior treatment.